Cristy Lee has a hard time convincing her friends about the endearing qualities of her hedgehog, Siu-Dak, which means 'Pokey' in Chinese. Every time she introduces her nine-month old spiny mammal to them, he curls up into a ball.

'When I first got Siu-Dak, he wasn't that scared,' Lee says. 'But since he's got older, he's become more scared of sounds, and if a stranger goes near him, he'll curl up into a ball, so he's very challenging to play with [when friends are around]. But whenever he does get scared, Siu-Dak only stays in a ball for a minute or two, and then becomes normal.'

Lee adopted her hedgehog in September last year, after one of her friends showed her a picture. 'Hedgehogs are so different from cats and dogs,' says the pet owner, who also owns a hamster, a dog, two cats, a tortoise and fish. 'They are about the size of your hand and have very soft fur, like cats and dogs. I let it walk around [outside its cage], and up my arms and around my neck.'

Veterinarian Gillian Hung, at Happy Pets Veterinary Centre in Tai Hang, started seeing hedgehogs in 2010. As these small mammals breed quickly, Hung has noticed more people keeping them as pets.

'They have a gestation period of about a month-and-a-half, not as quick as hamsters, but still fast,' Hung says. 'So that's why, apart from being cute, it's easy to breed them. The government doesn't give out licences to sell them in pet shops, but you can adopt them from people.'

Another reason why these creatures breed so quickly is their owners think they have two same-sex hedgehogs when they actually have a male and a female together in the same cage.

The veterinarian says: 'When hedgehogs are young, they are about half the size of your hand, so it's difficult to sex them, just like hamsters.' A male hedgehog's penis sheath is high on its underside, which often is confused as the belly button. Female hedgehogs have their vulva in front of the anus and tail.

According to Hung, the most common domesticated hedgehog in Hong Kong is the African Pygmy. With an average lifespan of three to five years, hedgehogs are physically more similar to guinea pigs, but have of a personality more like a hamster, the vet says.

'They get scared of a lot of things,' she says. 'And when they are timid, they curl up in a ball. But if you have them when they are young and handle them a lot, they will become more sociable. If they aren't handled enough, they can bite and are more difficult to examine.' Hung usually needs to administer an anaesthetic gas for timid hedgehogs before he checks them properly.

The veterinarian says hedgehogs are generally quiet and easy to keep. However, these nocturnal animals can be noisy at night from scurrying around their cages or running on their exercise wheels.

In setting up housing arrangements, Hung recommends using modified storage boxes with smooth sides. She doesn't advise using wire cages since the space between the wires can trap a hedgehog's legs. For bedding, it's best to use non-scented and non-oiled wood shavings.

Don't use cedar wood shavings as hedgehogs are allergic to this wood type, nor your everyday towels, which can end up being an unhealthy chewing snack.

Other comforts of home should include a hiding spot, possibly made out of a cardboard box that has been flipped upside down; a food and water bowl; and some toys.

How often you should clean your hedgehog's cage depends on each individual pet; some hedgehogs are cleaner than others.

However, if you want to clean the cage less often, Hung says some hedgehogs can be trained to use a litter box. But don't get too hopeful, not every hedgehog can learn this skill. At the other end of the hygiene spectrum, carefree hedgehogs 'will pee and poo at the same time, all around the wheel', Hung says. 'They can't seem to help themselves.'

In order to learn whether you have a trainable litter-box hedgehog, place some of your pet's droppings in an old tissue box filled with clumping or non-clumping cat litter. Then, wait and see if your little critter gets the hint to relieve itself in the box.

For hedgehogs that are on the dirty side, Hung suggests bathing them every two to three weeks. However, owners can clean their feet every day. Simply place your pet in a tub with shallow water, and use normal pet shampoo over their spines. Then brush your hedgehog's spines and coat with a toothbrush and use water to rinse.

'Initially they can be a bit nervous when they take a bath, but they get used to it,' Hung says. 'I don't think it stresses them out too much. Just keep the water nice and warm.'

Hung advises a daily menu of low-fat cat food, mealworms and crickets. When it's snack time, owners can give their little spiny ball a small slice of an apple, a sliver of strawberry, berries and melon. While fruits are nutritious, they are also high in sugar, so treats should be limited.

Three common problems among hedgehogs are obesity, skin problems (allergies from wood shavings) and mites. As hedgehogs are prone to packing on extra weight, an exercise wheel is a must-have apparatus.

'If they are too fat, their armpits can turn yellow,' Hung says.

If some of these mammals get mites, they will lose their quills and get an itchy skin, which becomes raw from scratching.

And remember to take out and handle your pet hedgehog from its housing environment every day, Hung says, or it will turn timid.